Door-operating mechanism



Dec. 18, 1928. 1,696,176

D. W. CAMPBELL DOOR OPERATING MECHANISM Filed Sign. 25, 1925 3 Sheets-Sheet l I l u I aw/,0 MC/I/VPBELL .ar ///5 fl/TOF/VE rs Dec .'18, 1928. 1,696,176

D. W. CAMPBELL DOOR OPERATING MECHANI SM Filed Sept. 23, 1925 3 Sheets-Sheet 2 Dec. 18, 1928. 1,696,176

0. w. CAMPBELL noon OPERATING MECHANISM Filed Sept. 23, 1925 3 Sheets-Sheet 3 Patented Dec. 18, 1928.

UNITED STATES DAVID W. CAMPBELL, OF MINNEAPOLIS, MINNESQ'IA.

DOOR-OPERATING MECHANISM.

Application filed September 23, 1925. Serial No. 58,046.

This invention relates to a door operating mechanism and control means therefor whereby adoor may be quickly and efiieiently opened and closed or the motion of the door reversed during opening and closing movement.

It is an object of this invention to provide a simple and eflicient mechanism comprising a rotatable member driven by a motor and link mechanism connecting said member and door and arranged so that the maximum force is applied to the door at the initial or preliminary opening movement and the force decreased as the door opens so that it is substantially at a minimum. when the door is in wide open position.

It is also an object of the invention to provide such a door operating mechanism, as set forth in the preceding paragraph, the rotatable member referred to being adapted to rotate to close the door, and the maximum force being exerted on the door when it approaches its closed position.

It is also an object of the invention to provide a door operating mechanism comprising a rotatable motor driven member, and link mechanism connecting the same to the door, together with manually operable means for starting the motor and means operated by said rotatable member for stopping the motor with the door in open position.

It is also an object of the invention to provide a door operating mechanism for oppositcly swinging doors comprising a rotatable member for each door, a link mechanism connecting each rotatable member to its respective door, a motor for driving said rotatable members, a switch adapted to be moved to position to start said motor and open or close said doors and a member for controlling said switch to move the same to position to stop said motor, said last mentioned member being operated b cam means carried on each of said rotatab e members.

It is more specifically an object of the invention to provide a door operatin mechanism comprising a driven rotatab e memher or an arm, a swinging member pivoted about a fixed axis, a link connecting the free end of said last mentioned member and said door and an operating link connecting said first mentioned rotatable member or arm and said link.

It is a further object of the invention to provide a door operating mechanism, as set forth in the preceding paragraph, a track being provided adjacent the top of said door, a member connected to the door and slidable on said track, said swinging member pivoted about a fixed axis being disposed above said track and bent to extend below the same, said link which is connected to said member and said operating link being disposed below the plane of said track.

These and other objects and advantages of the invention will be fully set forth in the following description made in connection with the accompanying drawings in which like reference characters refer to the same parts throughout the different views, and in which,

Fig. .1 is a view in front elevation of the doors and operating mechanism;

Fig. 2 is a top plan view of Fig. 1 showing the doors in closed position;

Fig. 3 is a top plan view showing the doors in partially open position;

Fig. 4 is a top plan view showing the doors almost in wide open position;

Fig. 5 is a plan view of a switch Wiring diagram therein and operating means therefor; and

Fig. 6 is a plan view of a switch-used, the wirin diagram therefor and operating means there or.

Referring to the drawings, a pair of folding'doors 7 and 8 are shown and while these doors may be of any desired construction, in the embodinient of the invention illustrated, they are shown as being of folding type, each comprising a plurality of hinged panels.

The panels 7 a and 8 adjacent the free edge of the door will be called the outer panels, while the panels 7 b and 8 adjacent the hinge will angle bars connected by plates, said bracket being suspended from an overhead support, such as a ceiling 14, by suitable hanger members 15. A motor 16 is mounted on said bracket 13 and has a belt 17 running over a pulley on its driving or armature shaft,

which belt passes over and drives a pulley 18 secured to a shaft 19 extending longitudinally of bracket 13, which shaft has secured thereto a pair of spaced worm gears (not shown) meshing with a pair of worm wheel gears (not shown) which worm gears and worm wheel gears are housed in casings 19, the worm wheel gears being secured to and driving shafts 20 and 21 projecting upward through the casings 19, said shafts having secured to their upper end cam members 22. A control switch 23 to be-later described is also mounted on the bracket 13 between the casings 19 and a rod 24, which passes through the switch 23 is adapted to move the same, said rod 24 having its ends passing through and slidable in small bearings 29 secured to housings 19, the ends of said shaft 24 being disposed to be engaged by the cams 22. The shafts 20 and 21 each have secured at their lower ends below the bracket 13 arms 24, which arms are provided with elongated slots 24 adjacent their outer ends so as to be adjustably connected to operating links 25. The links 25 are pivotally connected at their other ends to intermediate points on links 26. The links 26 are pivotally connected at one end to brackets 26 secured, respectively, to the innerpanels 7 b and 8' of the doors, said brackets 26 extending sli htly above the top of the doors so that the planes of the links 26 are above the top surface of the doors, as are also the planes of the operating links 25. The other and outer ends of the links 26 are pivotally connected to the ends of members 28 illustrated as formed of fiat bars, the other ends of which are pivotally connected about a fixed axis to brackets 27 secured to the wall 30 or some equivalent support above the doors. It will be noted in Figs. 1 to 4, that the members or bars 28 are curved downwardly at their outer ends to be connected to links 26. The main portion of said bars 28 pass from the bracket 27 over tracks 31 and are bent downwardly to a point below the plane of these tracks so that links 26 are below said tracks 31. The tracks 31 are illustrated as cylindrical in shape and are suprted at their outer ends in brackets 32 adustably secured to the adjacent ,wall or other suitable support at the sides of the doors. The inner ends of tracks 31 are supported by a bracket 33 disposed substantially centrally above the doors and also secured to the wall 30 or similarly disposed equivalent support. The outer panels 7 and 8 of the doors have secured adjacent their free edges brackets 34 adjustably connected to upstanding forks 35 which are pivotally connected to bearings 36 adapted to slide on the tracks 31. Said tracks 31 have compression coiled springs 37 disposed thereon ad'acent the brackets 32. It will be noted that t e tracks 31 are inclined outwardly from the central portion of the doorstoward the hinged side of the doors.

For controlling the operation of the doors through the motor 16, the I switch, 23, as stated, is provided which is mounted on the bracket 13. This switch is shown more or less diagrammatically in Fig. 5. While various kinds of switches might be employed, and while the specific switch forms no part of the resent invention, the same will be SlllfiClGIlby described to clearly set forth the opera tion thereof in combination with the door operating mechanism.

. The switch comprises a movable plate or contact 40 adapted to be moved longitudinally to alternately engage other contacts 41 and 42, said contact 40 having a neutral position when the switch is open midway between contacts 41 and 42. The movable contact 40 is adaptedto be moved in opposite directions by solenoids 43 and 44. The solenoid 44 is arranged to be controlled by a magnet 45 and the solenoid 43 is arranged to be controlled by a magnet 46, the magnets 45 and 46 being respectively controlled by push button switches 47 and 48. In Fig. 5 the wiring diagram for the parts is shown including the motor 16 and a transformer 49 used to re duce the line voltage for use on the magnets 45 and 46. The switch comprises contacts 50 and 51 adapted to be engaged by contacts 52 and 53, respectively, which are carried by flexible strips or springs 54 and 55, IQSPGC". tively. The leads which are connected to the power line or source of current are shown as 56 and 57. The arrangement shown in Fig. 5 is for use with alternating current and the motor 16 is reversible, the same being shown as equipped with three wires. To drive the motor in one direction the current will enter through one wire and leavethrough the second wire and for reversing the motor the current will enter through the third wire and leave the motor through-said second wire. Attention is called to the fact that the rod 24 is shown in Fig. 5 slidable in bearings 25 and engageable by cams 22 carried on shafts 20 and 21.

In operation, the push buttons 47 and 48- will be disposed in convenient position in the are e or other buildin havin the doors 7 an 8. Assuming the oors to in closed position, as shown in Fig. 2, when it is desired to open the same, the push button 47 will be pressed. Current from the line wires 56 and 57 will pass to the transformer 49 and when button 47 is closed a circuit will be completed through magnet 45. This magnet is arranged as a solenoid and equipped with a plunger core which will, upon energization of the magnet, be projected against spring 54, bending said spring and causing contact 52 to engage contact 50. Push button 47 is only pressed momentarily and when the same is released, spring 54 returns to normal position shown in Fig. 5 and moves the core of magnet 45 to normal position. As contact 52 engages contact 50 the circuit is closed from line wire 57, the spring 54 and contacts 52 to contact 50, thence through the solenoid 44 back to the line wire 56. Solenoid 44 is thus energized and moves contact 40 into engagement with contact 42, thus closing the circuit from the line through the motor. The motor 16 is now driven and shaft 19 is driven as are the shafts 20 and 21 and arms 24 begin to revolve in the direction shown by the arrows in Fig. As arm 24 moves in a clockwise direction, operating link 25 is moved toward link 26 and the link 26 and member 28 swing about their pivots in a clockwise direction. Attention is called to the fact that operating link 25 is substantially alined with arm 24 and this, together with the positions of link 26 and member 28, gives a powerful action tending to initially break and open the doors 7 and 8. The motion of arm 24 and connected parts continues, as shown in Figs. 3 and 4, and it will be seen that o crating link 25 begins to swing at an ang e to arm 24 so that the opening speed of the doors is increased and the force applied to the doors is decreased. The arm 24 continues its movement, moving past the position shown in Fig. 4 until it is substantially alined with operating link 25. When the doors are in wide open position, therefore, the force exerted on the same is substantially a minimum. As arm 24 and shaft 20 rotate the cam 22 rotates with shaft 20 and as the doors reach open'position, the wide part of cam 22 engages rod 24 and .moves the same to the left. This rod is connected to movable contact 40 and the plunger core of solenoids 44 and 43 and when so moved by cam 22 on shaft 20 moves the movable contact 40 to neutral position disengaging the same from contact 42. The circuit is now broken through motor 16 and the mechanism comes to rest with the door in open position.

When it is again desired to close the doors, the operator will press push button 48 and this will close the circuit from transformer 29 through magnet 46. This magnet will move its core plunger against spring and engage contacts 53 and 51. As soon as push button is released, spring 55 will resume its normal position and move the core. plunger of magnet 46 to normal position. When contact 53- and 51 engage a circuit is closed through solenoid 43 from the line 5657 and movable contact 40 is moved into engagement with contact 41. This closes the circuit from the line through the motor 16 in a reverse direction to that previously made. The motor is thus again started into operation in a di rection opposite to that in which it moved to open the doors. Arms 24 are thus moved in a counter-clockwise direction and the doors are moved to closed position as the arms 24 again approach the position shown in Fig. 2. In this reverse movement the maximum force exerted is placed on the doors just as they approach and come to closed position, such force increasing from the beginning of the closing movement. The speed of the doors as they come to closed position is also at the minimum. It is very desirable to have the maximum forceapplied to the doors as they are initially opened. The doors are sometimes inclined to stick or are sometimes slightly I frozen in closed position. Considerable force is also necessary to break the doors when folding doors are operated. With applicants device the force is substantially at a maximum during this breaking and preliminary movement. The force is slowly applied so that there is no great jar or shock transmitted to the doors. After the doors have been initially opened the speed is increased during the intermediate opening period and, as stated, the power is then decreased and the doors brought gently to wide open position. When the doors are initially opened it is impossible for a person to prevent the movement thereof with the motor operating. After the doors, however, have been opened a substantial distance the doors can be held against the power of the motor with little effort, the leverage possessed by the person holding the doors being sufficient to cause the motor belt to slip. As the doors reach their closed position the cam 22 on shaft 21 engages the end of rod 24 and moves contact 40 to neutral position, thus stopping the motor- The motor 16 can be reversed at any time after the doors have started to open or close, if such reversal is desirable for any reasonand this can be done by pressing the push button 48, if the doors are opening, or pressing push button 47 if the doorsare closing. The doors will then return to open or closing position, as the case may be and the motor and doors will be stopped by operation of the cams 22. The springs 37 are provided to assist in bringing the doors gently to open position, this spring being engaged by the slidable block or bearing 36. The springs are thus compressed when the doors are in wide open position and assist in overcoming the inertia of the doors as they start their movement toward closed position.

When the device is to be operated with direct current, a different reversing and operating means is necessary. In this case, the rod 24 is eliminated with its bearings 25 and the cams 22 on shafts 20 and 21 are used to operate auxiliary switches 60 and 61. A different type of switch 62 is used coi'nprising magnets 63 and 64 controlled, respectively, by push buttons 65 and 66 which magnets and push buttons circuits are supplied with current from a battery 67. Starting and stopping solenoids 68 and 69 are used to control a movable contact 70 adapted alternately to engage contact 71, 71 and 72. Reversing solenoids 7 3 and 74 are used to control a movable contact 75 adapted alternately to engage with contacts 76, 76 and 77, 7 7 and magnets 68 and 64 each have a plunger core adapted to engage springs 78 and 79, respectively, which springs, respectively, carry contacts 80 and 81 which, in turn, respectively, engage contacts 82 and 83. The leads to the line or source of current are shown as 8i and 85.

Assuming the parts of switch 62 to be as shown in Fig. 6, except that movable contact is in the position indicated in dotted lines, the doors 7 and 8 will be in closed position, as shown in Fig. 2 and arms 2e will be in the position shown in Fig. 2. To open the doors the push button 65 will be operated and the circuit will be closed from battery 67 through magnets 63. Magnets 63, by its plunger will move spring 78 to engage contacts 80 and 82. As soon as the push button 65 is released the spring 78 will swing back to normal position and will move back the plunger of magnet 63. Then contacts 80 and 82 engage, thecircuit is closed through solenoid 69 and from solenoid 69 through contact 72 and 70 back to the other side of the line. The solenoid 69 now is energized and it moves the movable contact 70 into engage ment with contacts 71 and 71. By engagement of contacts 70 and 71 a circuit is closed from the line through motor 16. The motor is now started and the arms 24:, as before described, move in a clockwise direction. As the door reaches wide open position, cam 22 on shaft 20 engages the switch 60 and momentarily closes the same. WVhen switch 60 is closed the circuit is closed through sole noid 68, and movable contact 70 is moved to the right, as shown in Fig. 6 into engagement with contact 72 and out of engagement with contacts 71 and 71. The contact 71 is used to complete this last mentioned circuit through solenoid 68, the circuit passing from the side 85 of the line through switch 60 to the wire leading from the conduit joining switches 60 and 61 then upwardly and across at the top of Fig. 6' to solenoid 68 and from this solenoid through contact 71 movable contact 7 0 back to the side 84 of the line. When movable contact 70 disengages contact 71* the circuit is broken through motor 16 and the doors come to rest in open position. There is enough momentum to the doors to carry the point of cam 22 past the engaging surface on switch 60. When it is desired to close the doors, push button 67 is again pressed and the operation is repeated, as already described, the motor being started by engagement of contacts 7 0 and 71" and continuing until cam 22 on shaft 21 momentarily closes switch 61. This energizes solenoid 68, the circuit passing substantially, as before described, through said solenoid, and contacts 70 and 71 are disengaged, thus stopping the motor with the doorsin closed position.

If it be desired to reverse the doors at any time during the closing or opening movement, the push button 66 will be operated. This will close a circuit from button 66 through magnets 6e and this magnet will operate and move its plunger against spring 79, thus engaging contacts 81 and 83, spring 79 and magnet 6l being moved to normal position when push button 66 is released. When contacts 81 and 83 are engaged the circuit is closed from line 85 through the resistance shown at the top of Fig. 6, to sprin 79, thence through contacts 81 and 83 and t irough solenoid 74, current passing from solenoid 74 through contact 77 across to movable contact 70 and back to the other side 8 10f the line. Movable contact 75 is now moved into engagement with contact 76 and the circuit is reversed through the motor 16. The motion of arm 24 will now be reversed with the reversal of: the motor and the doors will be moved to open or closed position, as the case may be, and the motor will be stopped when the doors reach such positions by one or the other of cams 22. If the switch button 65 be operated after switch button 66 has been operated, it will, in addition to entering the motor, as already described, by actuation of solenoid 69, also actuate solenoid 7 3 and the movable contact 75 will be moved into engagement with contact 77 and 7 7 a so that the solenoid 74 and movable contact 75 will be in position to again reverse the motor upon operation of push button 66. The circuit throu h solenoid 7 4: caused by operation of push button 65, may be traced from the side 85 of the line through the resistance at the top of Fig. 6, through springs 78, contacts'80 and 82, from the latter to the solenoid 73, thence to contact 76 and movable contact 75 which is then in engagement therewithacross to movable contact 70 and from the latter t the side 84 of the line.

From the above description it is seen that with direct current two push buttons are used as before, one of which controls the normal opening and closing of doors the other of which is used to reverse the motorat any time desired. The operation of the mechanism with the direct current motor is substantially the same as alread described with the alternating current witi the exception that in the normal opening and closing of doors by control button 65, the arms 24 move continuously through 360 degrees and are not reversed in the closing movement of the doors. The action of the link mechanism is the same as already described and the force is applied in the same manner.

From the above description it is seen that applicant has provided a very simple and efficient door operatin mechanism. The parts are very few in num er, simple and rugged in construction and so disposed that the most effective and desirable action on the door is obtained. The invention is designed for use with heavy garage doors and the same can be economically and easily installed and operated. The device has been amply demonstrated in a large number of commercial institutions and found to be very successful and efficient. The parts operate practically indefinitely without' requiring any attention. Some of the installations have now been in use over a year and have required no' attention except oiling at long intervals.

v It will, of course, be understood, that various changes may be made in the form, details, arrangement and proportions of the parts without departing from the scope of applicants invention, which, generally stated, consists in a device capable of carrying out the objects above set forth, in the novel parts and combinations of parts disclosed and defined in the appended claims.

What is claimed is:

1. A door operating mechanism for a pair of swinging doors having in combination, a rotatable shaft for each door at the side of the door which it opens and rotating on an axis substantially parallel to the free edge of said door, a motor for driving both shafts through a belt, a reduction gearing, an arm on said shaft rotatable therewith, a link mechanism connecting each arm to its respective door, a switch for controlling said motor to-stop the same, and an operatin member for said switch actuated from bot of said shafts.

2. A door opening mechanism for a folding door comprising an arm oscillatable in a' plane substantially at right angles to the free edge of said door, a swinging member above the door having one end pivoted about a fixed axis and'projecting over said door, a track above said door, a member secured to the door adjacent the free edge of said door and movable on said track, a link pivotally connected to the free end of said swinging member and to said door adjacent the h1ngedend of the latter, and an operatin link connecting said arm and said last mentioned link.

3. A door opening mechanism for a fold ing door comprising an arm oscillatable in a plane substantially at right angles to the free edge of said door and about an axis at the side of the door, said axis being nearer the free edge of the door than the hinged edge thereof with the door in closed position, a

swinging member above the door having one end pivoted about a fixed axis and projecting above said door, a link pivotally connected to the free end of said swinging member and to said door, and an operating link connecting said arm and said last mentioned link, a shaft carrying said arm, a motor for driving said shaft, and means connected to said shaft for controlling said motor.

4. A door opening mechanism for a folding door comprising an arm oscillatable in a plane substantially at right angles to the free edge of said door, a swinging member above the door having one end pivoted about a fixed axis and projecting over said door, a track above said door, a member secured to the door adjacent the free edge thereof and movable on said track, said swinging member being bent to project below said track, a link pivotally connected to the free end of said swinging member and to said door adjacent the hinged end of the latter, and an operating ,link connecting said arm and said last mentioned link.

5. A door operating mechanism for double doors comprising an arm for each door mounted for turning movement, said arms being movable in opposite directions about axes extending substantially parallel to the free edges of said doors toward which the doors open, articulated means connecting each arm to its respective door, a motor fordriving said arms, a switch movable to position to start said motor, a cam movable with each of said arms, and a member engageable by both of said cams for moving said switch to position to stop said motor when said doors are in wide open and closed positions, respectively.

6. A door operating mechanism having in combination, a driven shaft in front of said door and extending substantially parallel to the free edge of said door and toward which said door swings open, an arm secured to said shaft and movable in a plane substan-v tially at right angles to said axis, a guide track for said door extending at an angle to the plane thereof when the doors are closed, means carried by said door slidable on said track, a swinging member pivoted to the wall adjacent the hinged edge of the door, a link pivotally connected to the outer end of said swinging member and pivotally connected at its other end to said door, and an operating link pivotally connected to an intermediate point on said link and pivotally connected at its other end to said first mentioned arm.

7. A door operating mechanism for opening and closing oppositely swinging doors having in combination, a pair of turnable shafts disposed on axes substantially parallel with the free edges of said doors, an arm carried by each of said shafts and turnable in a plane substantially at right angles thereto, members respectively pivoted to fixed axes adjacent the hinged edges of said doors, link mechanism respectively connected to each of said members, said arms and said doors, a motor for driving said shafts, a switch movable" to starting, reversing and neutral position, manually operable control means for moving said switch to starting and reversing positions to open and'close said doors, res ectively, a member extending between sai shafts and connected to said switch and cams on, said shafts engaging said last neutral position to stop said motorwith said doors in wide open or closed position.

8. A door operating mechanism for swin ing doors having in combination, a turnab e member for each door, a shaft carrying each member, a swinging link mechanism for each door, means respectively connecting said link mechanisms and said rotatable members, a motor for driving said rotatable members, a manually operable control means for star ing said motor, and means including a member extending between said shafts and actuated by cams thereon for stopping said motor with said door in wide open or in closed position,

9. IL door operating mechanism having in combination, a member pivoted about a fined axis adjacent the hinged edge of said door and adjacent the plane of said door when the door is closed and toward which said door ope is, a driven arm turnable in a plane substantially at right angles to the free edge of said door, a track extending above said door inclining away from the plane of the closed position of said door toward its hinged end, said track being disposed below said member, means carried by the door movable on said track, and links connecting said arm, said member and door whereby when said arm is driven, said door is o ened.

10. ihe structure set orth in claim 9, and means for reversing the direction of turning of said arm when moving said door to closed position.

ll. A door operating mechanism for opening and closing a folding door havin in combination, a member pivoted about a nxed axis and adjacent the inged edge of said door and closely adjacent the plane of said door when the door is closed, a driven arm turnable in a plane substantially at right angles to said axis and toward which the door opens, a track extending above said door toward its hinged end, means carried by said door adjacent free edge thereof and movable on said track, a link connected to the end or" said first mentioned member and to said door between the hinge thereof and said last mentioned means, and a link connectin said arm to an intermediate point on sai last mentioned link, whereby when said arm is driven, said door is folded and opened.

12. The structure set forth in claim 11, said member being disposed above said track adjacent its fixed end but disposed below the same at its swinging end at the side of the track remote from said door, said links being disposed above said door and below said track.

13. The structure set forth in claim 3, said means com risin a cam carried by said shaft, a switch a aptef to be operated to stop said motor and a member operated by said cam for actuating said switch.

eeann 14. A door operating mechanism having in combination, a driven shaft turnable on an axis disposed at one side of the door and extending substantially parallel to the free edge of said door, an arm carried by said shaft and movable in a plane substantially normal to said axis, a member swinging about a fixed axis disposed between the free edge of the door and the hinged edge thereof, a member pivotally connected to said door between the free edge and hinged edge thereof and pivotally connected to said first mentioned member, link connected to said last mentioned member at an intermediate point therein, and pivotally connected to said arm.

15. A door operating mechanism having in combination, a swinging member pivoted to a fixed axis above said door, a. link pivotally connected to said member and to said door, an operating link connected to said link at an intermediate point therein, and a driven turnable arm connected to said operating link, said parts being arranged so that said operating link and said driven arm are substantially alined when said door is in closed position and said first mentioned link is disposed substantially at right angles to the plane of the door whereby a great force is exerted on said door during the initial opening movement thereof, which force decreases as said door swings to open position and is substantially at a minimum with the door in wide open position.

16. A door operating mechanism having in combination, a driven member turnable in a plane substantially perpendicular to the free edge of said door and about an axis in front of said door and toward which the door opens, a swinging member above said door pivoted at one end about a fixed axis, a link pivotally connected to the door and to the end of said swinging member and extending substantially at right angles to said door when the door is in closed position, and means connecting said first mentioned member and said link for opening and closin said door by the turning movement of said first mentioned member.

17. A door ,operating mechanism for a bin ed door havlngin combination, a driven sha turnable about an axis toward which the door opens, an arm carried by said shaft and movable in a plane substantially at right anglesto said axis, amember-swinging about a fixed axis dis osed between the free edge of the door and t e hinged edge thereof when the door is closed, a member pivotally connected to the door between the free edge and hinged'edge thereof and pivotally connected to said first mentioned member, said first mentioned member when the door is in closed position, crossin said last mentioned member intermediate t e ends thereof and making a v comparatively small angle thereto and a l1!1k connected to said last mentioned member at an intermediate point therein and pivotally connected to said arm.

18. A door operating mechanism for a hinged door having in combination, a driven shaft turnable about an axis toward which the door opens, an arm carried by said shaft and movable in a plane substantially at right angles to said axis, a member swinging about a fixed axis disposed between the free edge of the door and the hinged edge thereof when the door is closed, a member pivotally con nected to said door between the free edge and hinged edge thereof and pivotally connected to said last mentioned member, a link connected to said first mentioned member at an intern'iediate point therein and pivotally connected to said arm, a motor, a driving mechanisni between said motor and said shaft,

means for reversing said motor whereby said shaft is rotated through a certain angle to open said door and then rotated reversely to close said door, said shaft and arm being capable of rotation through 360 upon failure of any part of the control mechanism to stop the motor.

19. A door operating mechanism for a hinged door having in combination, a driven shaft turnable about an axis toward which the door opens, an arm carried by said shaft and movable in a plane substantially at right angles to said axis, a member swinging about a fixed axis disposed between the free edge of the door and the hinged edge thereof when the door is closed, a member pivotally connected to said door between the free edge and hinged edge thereof and pivotally connected to said last mentioned member, a linkconnected to said last mentioned member at an intermediate point therein and pivotallyconnected to said arm, said fixed axis being located near the hinged edge of the door and the pivotal connection ofsaid lastmentionedmember with the door when the door is closed, said parts being so arranged that when thedoor is closed, said arm is on the side of said shaft away from the door, substantially alined with said link, with said member pivotally connected to the door disposed substantially at right angles to the door, and when said door is in open position, said member extends substantially parallel to the plane of the door in closed position and substantially alined with said link.

20. A door operating mechanism for a hinged door having in combination, a driven shaft turnable about an axis toward which said door opens, an arm carried by said shaft and movable in a plane substantially at right angles to said axls, an arm pivot-ed about a fixed axis at one end between the free edge of the door and the hinged edge thereof when the door is closed, a link pivoted at one end to the other end of said arm and ivotally connected to said door between the res edge and hinged edge thereof, said last named arm being longer than said link and making a small acute angle therewith, a second link pivotally connected at one end to said first named link and pivotally connected at its other end to said first named arm.

21. A dooroperating mechanism for a hinged door having in combination, a driven shaft turnable about an axis extending substantially parallel to the free edge of said doorand toward whichsaid door opens, an arm carried by said shaft and movable in a plane substantially at right angles to said axis, an arm pivotally connected at one end about a fixed axis disposed between the free edge of the door and the hinged edge thereof, a link pivotally connected to the other end of said last named arm and pivotally con nected to said door between the free edge and hinged edge thereof, said first named axis.

being disposed a distance away from the plane of the door greater than the length of said first named link and a link connected intermediate the ends of said first named link and connected to said first named arm.

, 22. A door operating mechanism for a hinged door having in combination, a driven shaft movable about a fixed axis extending substantially parallel to the free edge of said door and toward which said door opens, an arm carried by said shaft and movable in a plane substantially at right angles to said axis, an arm pivotally connected about a fixed axis at one end disposed normally adjacent the plane of said door and between the hinged and free edges thereof when the door is closed, a link connected to the other end of said arm and pivotally connected to said door and extending substantially at right angles to said door when said door is in closed position and crossing said arm between the ends thereof at an acute angle when said door is in closed position, and a link pivotally connected to said link intermediate the ends thereof and connected at its other end to said first named arm.

23. A door operating mechanism for a hinged door having in combination, a driven shaft turnable about an axis extend ing substantially parallel to the axis about which the door swings, an arm carried by said shaft and movable in a plane substantially at right angles to said axis, an arm pivotal- 1y connected about a fixed axis at one end, said last named axis being disposed adjacent the plane of the door when the door is in closed position, a link connected to the other end of said last named arm and pivotally connected to the door, said link extending substantially at right angles to said door when said door is in closed position, and a second link pivotally connected at one end to said first named link intermediate the ends thereof and connected at its-other end to said first named arm.

LIL

2 1. A door operating mechanism having in combination a frame disposed above said door, a motor supported on said frame, a Worm gear driven from the shaft of said motor, a Worm Wheel gear driven by said Worm gear, a pivot member movable in an are by said Worm Wheel gear and a link connected to said pivot member and to a member connected to said door, whereby said door is opened b* rotation of said Worm Wheel gear.

25. The structure set forth in claim 24, said pivot member having an axis parallel to the axis or" said worm Wheel gear.

26. A door operating mechanism having in combination, a frame disposed above said door, a shaft carried by said frame disposed in front of said door at some distance therefrom, a gear rotated about the axis of said shaft, means meshing with said gear for driv ing the same carried by said frame, a motor on said frame for driving said means, a pivot member moved in the arc of a circle by said gear, a link connected at one end to said pivot member, and a member connected to said door to which the other end of said link is connected.

2'2. A door operating mechanism for operatin oppositely swinging doors having in combination, a frame disposed above said doors, a pair of gears mounted on said frame and spaced apart in a direction parallel to the plane of said doors when closed, means for driving said gears, a motor on said frame for drivingsaid means, pivot members moved in the arc of a circle by each gear, respectively, a link connected at one end of said pivot member, and a member connected to said door te which the other end of said link is connected, said gears rotating in opposite directions.

28. A door operating mechanism having in combination, a link disposed above said door and connected to a fixed vertical axis above said door, means connected to said link and to the door for moving said door comprisan arm pivotally connected at one end to the end of said link, a shaft carrying said arm, a gear for drivin said shaft, means for drivng said gear, and: a motor for drivin said means, said arm being rotated by sai motor for moving said door.

in testimony whereof I afiix my signature.

DAVID W. CAMPBELL. 

